The liver cleanses the body of foreign substances, produces blood clotting factors, aids in food digestion and metabolizes most drugs. Viral infections, alcohol abuse, toxic poisoning, and autoimmune disease are potential causes of liver injury. Symptoms of liver problems include nausea, vomiting, fatigue, weakness and lack of appetite. A review published in the "Lancet" in July 2010 reported that drug-induced liver disease is the second leading cause of acute liver failure.
Acetaminophen
Acetaminophen, commonly marketed as Tylenol, is frequently used for pain, fever and arthritis. Over-the-counter products and prescription medications contain acetaminophen, making it easy to accidentally overdose. Exceeding the maximum dose of 4g per day can lead to acute liver injury and possibly death. Acetaminophen is converted into a toxic metabolite that binds with proteins in the liver, causing injury to liver cells. Individuals who drink alcohol or have pre-existing liver disease are more sensitive to acetaminophen and potential liver injury.
Isoniazid
Isoniazid is commonly used to treat tuberculosis and may injure the liver's cells similar to acetaminophen. Mild increases in liver enzymes is common, occurring in 10 to 20 percent of those who take isoniazid, according to Merck. Discontinuation is unnecessary, but a doctor will monitor the liver enzymes periodically. In some cases, liver injury can progress to permanent liver damage or death. Isoniazid discontinuation is warranted in severe cases of liver damage, which is more common in older people.
Statins
Statins, such as atorvastatin and simvastatin, are medications used to treat high cholesterol. Since these medications are metabolized by the liver, there is potential for liver injury. Statins can cause mild liver enzyme elevations, which normally subside with drug discontinuation and cause no harm. The National Lipid Association Safety Task Force reported in 2005 that no evidence exists proving statins cause fatal liver damage. Manufacturers of statin drugs do, however, recommend routine liver enzyme monitoring.
Antiretrovirals
Antiretrovirals are medications used to treat human immunodeficiency virus. These medications are often used in combination, resulting in additional risks to the liver. People with HIV are also more likely to have underlying liver diseases, such as hepatitis B or hepatitis C. Injury to the liver occurs by cell damage and can be lethal. Nevirapine carries a high risk of liver toxicity and liver enzymes must be monitored very closely for the first 16 weeks of treatment, explains the University of California, San Francisco. As with all medications, the benefit must outweigh the potential risk of side effects.
